72 Herculis
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| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Hercules |
| Right ascension | 17h 20m 39.567s |
| Declination | +32° 28′ 03.88″ |
| Apparent magnitude (V) | 5.377 ± 0.005[1] |
| Characteristics | |
| Spectral type | G0 V |
| U−B color index | 0.07 |
| B−V color index | 0.62 |
| Variable type | Suspected |
| Astrometry | |
| Radial velocity (Rv) | -78.7 km/s |
| Proper motion (μ) | RA: 135.41 mas/yr Dec.: -1040.65 mas/yr |
| Parallax (π) | 69.48 ± 0.56 mas |
| Distance | 46.9 ± 0.4 ly (14.4 ± 0.1 pc) |
| Absolute magnitude (MV) | 4.43 ± 0.05[1] |
| Details | |
| Mass | 0.91[1] M☉ |
| Radius | 1.17 ± 0.04[1] R☉ |
| Surface gravity (log g) | 4.26 ± 0.10[1] cgs |
| Temperature | 5,625[2] K |
| Metallicity [Fe/H] | -0.60[2] dex |
| Rotational velocity (v sin i) | 1.0 ± 1.0[1] km/s |
| Age | 4.1–6.6[3] Gyr |
| Other designations | |
72 Herculis is a main sequence dwarf star in the constellation Hercules. The Flamsteed designation for this star comes from the publication Historia Coelestis Britannica by John Flamsteed. It is the 72nd star in Flamsteed's list of stars in Hercules.
Based on its spectral classification of G0 V, it is similar in mass and luminosity to the Sun. Parallax measurements show this star to be about 47 light years from the solar system. The photosphere shows an effective temperature of 5,625 °K[2] and a metallicity (Fe/H) equal to -0.60 ± 0.20.[2]
The Washington Visual Double Star Catalog for 1996 showed two visual companions of this star. The first is a visual magnitude 9.7 star located 289.1 arc seconds away. The second is only separated by 8.7 arc seconds, and is magnitude 12.9.[4] It is unknown whether these visual companions are gravitationally-bound to 72 Her.
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Fuhrmann, Klaus (February 2008), "Nearby stars of the Galactic disc and halo - IV", Monthly Notices of the Royal Astronomical Society 384 (1): 173–224, Bibcode:2008MNRAS.384..173F, doi:10.1111/j.1365-2966.2007.12671.x
- ↑ 2.0 2.1 2.2 2.3 G. Israelian, R.J.L. García, R. Rebolo (1998). "Oxygen Abundances in Unevolved Metal-poor Stars from Near-Ultraviolet OH Lines". The Astrophysical Journal 507 (2): 805–817. arXiv:astro-ph/9806235. Bibcode:1998ApJ...507..805I. doi:10.1086/306351. Retrieved 2006-08-17.
- ↑ Mamajek, Eric E.; Hillenbrand, Lynne A. (November 2008). "Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics". The Astrophysical Journal 687 (2): 1264–1293. arXiv:0807.1686. Bibcode:2008ApJ...687.1264M. doi:10.1086/591785.
- ↑ C.E. Worley, G.G. Douglass (1997). "The Washington Visual Double Star Catalog" (abstract page). Astronomy & Astrophysics Supplement Series 125.
External links
- "HD 157214 -- Variable Star". SIMBAD: Centre de Données astronomiques de Strasbourg. Retrieved 2006-08-17.
- "1720+3228". NStars database. Retrieved 2006-08-17.
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